Silencer and solid particle separator



Nov. 27, 1945. R. L. LEADBETTE R 2,339,983

SILENCER AND SOLID PARTICLE SEPARATQR Filed Nov 21, 1943 2 Sheets Sheet l V a wwmwwww fl 3 0000000 oOOOOOo oOOOOOo W M Z Z Z i 3 if J Nov. 27, 1945. R. L. LEADBETTER SILENCER AND SOLID PARTICLE SEPARA'IOR Fild Nov. 21, 1943 2 Sheets-Sheet 2 O O 0 0 000000 0000000000000 fl 000000 0000000000000 7 mwwwww wwwwwwwwwwwww 000000 00 00 i wwwwwww 00 o 0V6 00000 0 0 6 3 5% w M i i IIJ Patented Nov. 1945 SILENCEB, AND SOLID PARTICLE SEPARATOR Ral h L. Leadbetter, Wheaten, nr, assignor, by

Mannin Commesne assignments, to Burgesspany, Chicago, 111., a corporation of Illinois Application May 21, 1943, Serial No. 487,888

11 Claims. (01. 181-36) This invention relates to improvements in devices for acting upon streams of pulsating gases, such as the exhaust gases or internal combustion engines, to prevent the formation of noise thereby. In particular, it relates to that form of device in which the velocity peaks of the gas pulses, or slugs, are snubbed by being allowed to expand in a chamber and then pass out of the chamber by filtering through the openings in the walls of apertured walled conduits which lead out of the chamber. A device of such character is described in Chipley U. 8. Patent 2,205,899, granted June 25, 1940. The improvement ot-the present invention their axes oblique to the axis of the chamber whereby the length of the conduits within the chamber, and the effectiveness of the action of the device upon the gas slugs, are increased. In addition, as a result of the oblique arrangement of the conduits, the gases emerging therefrom are given a whirling motion which may be utilized for causing a separation of sparks, or other solid particles, from the gases.

It is, accordingly, the object of the invention to provide a device of the character described which exhibits increased eflectiveness in the snubbing f the gas slugs and which inherently accomplishes the separation of solid particles from the gas stream, whereb the simple provision of a receptacle for such particles causes the device to operate as a solid particle separator as well as a silencer.- The device may be referred to herein as a silencer, but it is understood that this is done for convenience and brevity, and that the device operates to snub the pressure-velocity resides in the arrangement of the conduits with peaks, or slugs, and thus removes the primary cause of noise rather than silences the noise after it has been created.

In the accompanying drawings:

Fig.1 is a longitudinal sectional view of one embodiment of the invention;

Figs. 2 and 3 are transverse sectional views along lines 22 and 3-3 of Fig. 1;

Fig. 4 is a longitudinal sectional view of a different embodiment of the invention;

Figs. 5 and 6 are transverse sectional views along lines 5-! and 8-4 of Fig. 4; and

Fig. 7 is a fractional perspective view of a portion of the device of Fig. 4.

The embodiment shown in Figs. 1, 2 and 3 is adapted for arrangement with its axis extending horizontally and consists of a shell It of cylin drical shape, which has an inlet opening llin inlet end wall I! and an outlet opening it in outlet end wall It, and has two spaced-apart transverse partitions II and i6 dividing the interior of the shell into an inlet chamber il, a snubber chamber II and a separating chamber l9, arranged in succession proceeding from the inlet end wall. The end walls and partitions may be dished, as shown, for increased strength, and may be joined to the cylindrical wall of shell III by welding. The remainder of the parts of the structure are joined together in-a similar manner. An inlet conduit 2| passes through inlet opening il in a direction axially of the shell II and leads into the inlet chamber". The partition I! has a central opening 22 therein, which is in alignment with inlet conduit 2| and has an area at least substantially as large as the cross sectional area of inlet conduit 2i. To facilitate the flow of gases through opening 22, a lip 23 is provided at the edge of the opening, said lip extending into the snubber chamber i8.

Partition I! has a plurality of openings 24 spaced from the central opening 22, and preferably adjacent the cylindrical wall of shell III, as shown in Fig. 2. The openings 2| are spaced apart uniformly angularly with respect to the axis of the shell. Partition it has an equal number 01' openings 25 spaced from the center thereof and preferably adjacent the cylindrical wall of the shell, as shown in Fig. 3. Openings 2! are also spaced apart a uniform angular distance with respect to the axis of the shell. Apertured walled conduits 28 pass through the snubber chamber I 8 and are connected at their opposite ends to openings 24 and 25 respectively. The individual openings 01' each pair of connected openings are arranged in non-alignment with each other,

whereby the axes of conduits 26 extend in a; direction oblique to the axis of the shell. In the particular device shown in Figs. 1", 2 and 3 there are five openings in each of partitions l5 and it and five conduits 26. One of the conduits 26 extends between the specific opening 2| in partition [5 and opening 25' in partition [6. The individual openings of each connected pair of openings are uniformly displaced an angular distance of 72 with respect to each other, the eilect being as though the openings 25 were initially aligned with openings 24 and connected by conduits 26 extending in a direction parallel to the axis of the shell, and one of the partitions was then rotated through an angle of 72. That is, looking at the device from the outlet end (as viewed in Fig. 3), partition it has been rotated 72 in a clockwise direction with respect to partition l5.

The eflect of the arrangement is that conduits of substantially increased length can be accomthe near side of the lip 3| under high pressure and transversely the walls of conduits and through said conduits and into the separatconduits 26 and 2 2,889,988 modated within a snubber chamber of a given through said conduits into the separating chamlength. In the specific device shown in Figs. 1, her. As a result of this action, the slugsare 2 and 3. the conduits 26 are approximately 20% longer than they would be if they were arranged parallel to the axis of the shell. The increased length of the conduits is an important factor in obtaining improved snubbing action, as will be explained hereinafter.

A second efiect of the oblique arrangement of conduits 26 is that the gases emerging therefrom are given a whirling motion in the separating chamber l9, which may be utilized for effecting a separation of solid particles from the gases The separating chamber I! has a slot 36 in its side wall, extending generally longitudinally of the shell. The slot 36 is formed by making a longitudinal cut in the wall and pushing the material of the wall inwardly to form alip 3! which extends in an oblique direction toward the interior of the chamber, as shown in Fig. 3. The arrangement is such that the slot 36 is on in the path of the oncoming whirling gases. A receptacle 32 for solid particles is provided exteriorly of the shell Ill and in communication with the slot 36, the receptacle having bottom walls tapering downwar'dly to a clean-out opening 33 which may be closed-by a removable plug 34. Plug 34 may be removed periodically and the receptacle emptied of accumulated particles,

An open ended outlet conduit 36 passes through 7 outlet opening l3 and extends into the separating chamber I! to a point adjacent the partition IS. The walls of outlet conduit 36 are preferably imperforate for a portion of their length within the separating chamber adjacent the outlet wall II, and apertured for the remainder of their length within the separating chamber. Between the end of outlet conduit 36 and partition l6 a plurality'of vanes 31 are arranged to extend radially of the conduit 36, that is, with their broad surfaces in a plane extending substantially parallel to and passing through the axis 01' the outlet conduit.

In operation, the exhaust system of the engine is connected to inlet conduit 2| and the pulsating exhaust gases are discharged from said inlet conduit consist of a succession of slugs. each slug being traveling at high velocity and, therefore, possessing much inertia. The slug is projected from the end'of inlet conduit 2| directly across the inlet chamber l1 and through opening 22 in partition l5 andinto snubber chamber 16. It displaces the air or gas standing in inlet chamber l1, and this gas moves in said chamber and into the ends of conduits 26 and through said conduits and into into inlet chamber II. The gases.

' mately 2 times the the separating chamber l9. In snubber chamber I8, the traveling slug also displaces the gases present, which filter through the apertures in w 26 and'into said conduits duit u into the open ends or conduits a and "-tance such that the area of duits, and because of eifectively'snubbed and the gases pass into the separating chamber in a relatively steady stream. whereby the creation of noise is prevented. The action of the gases filtering through the apertured walls of conduits 26 is an important factor in producing the snubbing action. The pressure and velocity conditions at the outlet or each conduit are the resultant effect of the pressure and velocity conditions of the gases passing into the conduit through each aperture throughout the length of the conduit. There is a leveling-oil action within the .conduit,*by which an entering high pressure pulsation is suppressed. This levcling-oil action is increased with increasing length of conduit and the present invention provides a substantially increased length of conduit without any increase in the length of the apparatus.

The gases emerge from conduits 26 traveling in a direction parallel of the conduits the gases have acomponent of force in a direction transversely of the axis of the separating chamber, and when the gases strike the cylindrical wall of the chamber, this component produces a whirling motion of the gases within the chamber. As a result of this whirling action, solid particles which may be present in the gasesare thrown to the exterior of the vortex. 7 direction as to intercept the particles and direct them through the slot 30 and into the receptacle 32. The in outlet conduit 36 and also pass into the open end of said conduit. It has been found that improved separation of particles from the gases is obtained if the portion of the conduit wall. adjacent the shell outlet wall II is. imperforate as described heretofore, and that less restriction to the flow of gases through the device is oifered if vanes 31 are present. I whirling motion of the gases the conduit and the passage ofthe gases through the conduit is facilitated as a result.

For satisfactory operation, apertures in conduits 26 should not be so' great that the slugs pass through the conduit walls so readily that they do not undergo the desired passage of gas therethrough. It is preferred that the apertures in said conduits occupy an aggregate area of from approximately 0.75 to approxiaggregate cross sectional area of said conduits. The apertures in the outlet tube 36 preferably also occupy an area equal to approximately 0.75 to 2.0 times the cross sectional area of said conduit 36. Partition l5 should be spaced from the end of inlet conduit 2| a disis at least equal to the cross sectional area or directly from inlet conand contraction in the device, and,

the inlet conduit, that is, the area of the path which must be followed by the gas in escaping transversely from conduit 2| and passing into the ends of conduits 26 should be at least substan-' tially as great as the cross sectional area of inlet conduit 2|. In the same way, the end of outlet conduit 36 preferably is spaced from partition l6 a distance sumcient that the area of the space between such parts is at least substantially equal to the cross sectional area of the outlet conduit. The gases undergo cooling to the axes of said conthe oblique arrangement The lip Si is turned in such a.

gases filter through the apertures Such vanes arrest the entering the end of the area of the the gap between them as 8' results the outlet conduit may-.be somewhat smaller in cross sectional area than the inlet conduit. From the standpoints of silencing, particle separation and structure, the individual openings or each connected pair oi openings are preferably displaced angularly from each other from approxi! mately 45' to approximately 135;

In a specific application of a device of the construction shown in Figs. 1, 2 and 3 for use with a 2 cycle Diesel engine having 9 cylinders and a piston displacement per cylinder of 1037 cubic inches, and capable of developing a maximum brake horse power oi 1600 at 800 R. P. M., the shell II had a length of 89 inches (between the centers oi the dished end walls) and a diameter oi 42 inches; the chambers were of the following length, the inlet chamber 17 inches, the snubber chamber 40 inches and the separating chamber 32 inches; the inlet and outlet con-' spaced 14 inches from the partition II; the inlet' end oiv the outlet conduit was spaced 9 inches from partition II: the apertures in the walls of conduits 26 and 36 were 1 inch diameter openings spaced approximately 4 inches apart between centers, and the individual openings of each connected pair oi openings in partitions i and I 6 were-displaced from each other 72 angularly with respect to the axis of the shell.

The device shown in Figs. 4, 5 and 6 is adapted for use with the axis thereof extending vertically. The device consists of a generally cylindrical shell 40 having an inlet opening II in inlet end wall 42 and an outlet opening I! in outlet end wall 44, and havin spaced apart transverse partitions l5 and I6 dividing the shell into inlet chamber 41. snubber chamber 48 and separating chamber 49 arranged in succession proceeding from inlet end wall 42. inlet conduit 50 leads into inlet chamber 41, and an opening 5| is provided in partition 45 in substantial alignment with inlet conduit 5|. An apertured snubber receptacle 52 has its open mouth connected to opening 5|, and extends into the snubber chamber-'48. The partition l6 i'orms a closed end for said receptacle, opposite the open mouth thereof. Openings 53 clean-out opening II at the bottom thereof which may be closed by a removable plug ll.

An outlet conduit 62 passes through outlet opening 43 and extends into separating chamber 0. Straightening vanes II are arranged between conduit 6! and partition 46. The details of conduit 62 and vanes 08 are similar to the corregponding features of the device of Figs. 1, 2 and The operation or the device was. 4 is substantially the same as that of the device in Figs.

" l, 2 and 3. The gases enter by way of inlet conduit 5. and the slugs are projected directly and 5| are provided in partitions 45 and 46 re- I spectively, said openings being spaced from the centers or said partitions and being connected by apertured conduits which pass obliquely through snubber chamber 48 and provide direct communication between inlet chamber l1 and separating chamber 49 in an arrangement similar to that of conduits 26 of the device shown in Figs. 1, 2 and 3. The conduit 55 which is seen in Fig. 4 extends between the particular opening in partition 45 (see Fig. 6). The openings 53' and 5| are angularly displaced 90 with respect to each other. Lips 58 are provided at the outlet ends of conduits 55 within separating chamber 49, said lips being formed by cutting off the end of the conduit diagonally and bending inwardly the projecting portion of the conduit wall. The lip is arranged so as to impart to the emerging gases a directional component such that the obliqueness of the path of said gases is increased.

In the side portion of the wall of separating chamber 49, a slot 51 and an inwardly projecting lip 58 are provided, similar to slot 30 and lip 3| of the device 0! Figs. 1, 2 and 3. Exteriorly oi the slot is arranged a particle receptacle 59' extending the length of the shell and having a across the inlet chamber 41 and into the snubber receptacle 52. The apertured walls of such receptacle permit the expansion 01' the slugs within the snubber chamber 48, while exerting a slight restraining action upon such expansion so that the desired snubbing eilect is obtained. Ai'ter expanding within the snubber chamber, the gases filter through the apertured walls of conduits 55 and into said conduits and through said conduits into separating chamber 49. The lips 55 increase the obliqueness or the path of the gases as they emerge from the conduits 55 and, as a result, the whirling action and the eilectiveness of particle separation are increased. The action in chamber 49 is similar to that described heretofore in connection with separating chamber is of the device of Figs. 1, 2 and 3.

The invention is not limited to the specific embodiments which are shown and described, and various modifications thereof may be made. For example, the separation of particles from the gases may not be required, in which case the third chamber, corresponding to chamber is of Fig. 1, is simply an outlet chamber, rather than a separating chamber, and the side wall thereof does not contain a slot and lip for trapping particles, and the particle receptacle may be dispensed with. In such case, also, the length of the outlet chamber may be substantially less than that of chamber I8.

Lips 56 at the ends of conduits 55. (see Fig. 4) may be of the construction shown in Fig. '7. A separate lip member is mounted upon the end portion of conduit 55 projecting into chamber 49 by welding .or other suitable means, and is arranged at an angle to the axis of the conduit so as to impart the desired directional component to the emerging gases. It encircles the greater portion of the periphery of the conduit and its length gradually increases from one end to the other. The end portion of greatest length is arranged upon that side of the gas stream which is to receive the deflecting force.

The number of oblique conduits passing through the snubber chamber may be varied as desired. However, if the separation of particles is required, it has been found that the use of a single oblique conduitdoes not impart suflicient of a whirling motion to effect the substantially complete separation of the particles. The use of two oblique conduits provides satisfactory resuits, but better results are obtained from the standpoint of both silencing and particle separation, if more than two conduits are provided, and excellent results have been obtained with tour or five conduits. Also, while the dished shape'of the ends walls and partitions shown is preferred, such parts may be flat. In the same way, the lip 23 upon partition 15 may be omitted if desired. While the conduits within the device are shown as having a large number of round apertures in the walls thereof, the apertures may be of a shape other than round, and may be elongated slots extending longitudinally of the conduits.

I claim:

1. A device of the character described, comprising a shell, means forming an' inlet chamber, a snubber chamber and an outlet chamber in longitudinal succession in said shell, gas inlet conduit means leading into said inlet chamber, said snubber chamber having an inlet opening in direct communication andalignment with and spaced from said inletconduit means, a plurality of apertured walled conduits passing through said snubber chamber and providing communication between said inlet chamber and said outlet chamber, the axes of said conduits being oblique to the longitudinal axis of said snubber chamber, the inlet ends of said conduits being in nonalignment with said inlet conduit means, and gas outlet means leading out of said outlet chamber.

2. A device of the character described, comprising a shell, means forming an inlet chamber, a snubber chamber and an outlet chamber in longitudinal succession in said shell, gas inlet conduit means leading into said inlet chamber, said snubber chamber having an inlet opening in direct communication and alignment with and spaced from said inlet conduit means, a plurality of apertured walled conduits passing through said snubber chamber and providing communication between said inlet chamber and said outlet chamber, the interior of said snubber chamber being substantially free of obstructions whereby gases therein are substantially free to expand and pass into said conduits through the apertured walls thereof, the axes of said conduits being uniformly oblique to the longitudinal axis of said snubber chamber, the inlet ends of said conduits being in non-alignment with said inlet conduit means, said inlet chamber providing a transverse gas path between said inlet con.- duit means and said apertured conduits at least substantially as large as the cross sectional area oi. said inlet conduit means, and gas outlet means leading out ofsaid outlet chamber.

3. A device of the character described, comprising a shell, first and second spaced-apart transverse partitions dividing said shell into an inlet chamber, a. snubber chamber and an outlet chamber, a gas inlet conduit leading into said inlet chamber and having the outlet end thereof spaced from said first partition, said first partition having aprimary opening therein in direct communication and substantial alignment with said inlet conduit and a plurality of secondary openings therein in non-alignment with said inlet conduit, said second partition having openings therein spaced from the center thereof and equal in number to said secondary openings, open-ended, apertured walled conduits passing through said snubber chamber and connecting each of said secondary openings to one of said openings in said second partition and providing communication between said inlet chamber and said outlet chamber, the axes of said apertured walled conduits being oblique with respect to the axis of said snubber chamber, and gas outlet means leading out ofsaid outlet chamber.

4. A construction in accordance with claim 3, in which an open mouthed apertured walled receptacle is arranged within said snubber chamber in substantial alignment with said inlet conduit, the open mouth of said receptacle being in direct communication with the inlet chamber through the primary opening m the first partiaseaees tion and being spaced from the outlet end of said inlet conduit.

5. A device of the class described, comprising a generally cylindrical shell, first and second spaced-apart transverse partitions dividing said shell into an inlet chamber, a, snubber chamber and an outlet chamber, a gas inlet conduit leading into said inlet chamber, said first partition having a primary opening therein at least substantially as large as the cross sectional area of said inlet conduit and in direct communication and substantial alignment with said inlet conduit, said first partition having a plurality of secondary openings therein in non-alignment with said inlet conduit, said secondary openings being in unrestricted communication with the outlet end of said inlet conduit, said second par.- tition having openings therein spaced from the center thereof and equal in number to said secondary openings, open-ended, apertured walled conduits passing through said snubber chamber and connecting each of said secondary openings to one of said openings in said second partition and providing communication between said'inlet chamber and said outlet chamber, the individual openings of each of said connected pairs of openings being angularly displaced one from the other with respect to the axis of said cylindrical shell, whereby the axes of said apertured walled conduits extend uniformly obliquely with respect to said axis of said shell, and an outlet conduit extending into said outlet chamber from v the wall thereof opposite said second partition.

6. A construction in accordance with claim 5,

in which the mutual angular displacement of the individual openings of each connected pair of openings is from approximately degrees to approximately 135 degrees.

7. A construction in accordance with claim 5,

40 in which the apertures in the walls of each of the conduits traversing the snubber chamber occupy an aggregate area of from approximately to approximately 2 times the cross sectional area of said conduit.

8. A construction in accordance with claim 5, in which the distance between the outlet end of the inlet conduit and thefirst partition is suificient to provide a transverse escape path for the gases leaving said inlet conduit having an area at least substantially equal to the cross sectional area of said inlet conduit.

9. A construction in accordance with claim 5, in which means are provided in the outlet chamber adjacent the inlet end of the outlet conduit for arresting whirling motion or gases.

10. A construction in accordance with claim 5, in which a plurality of vanes are arranged within the outlet chamber adjacent the inlet end of the outlet conduit, said vanes being arranged length of the conduit.

generally radially with respect to the axis of said conduit and having their broad surfaces. in planes substantially parallel to and passing through the axis of said outlet conduit.

11. A construction in accordance in which the outlet conduit extends into the outlet chamber to a point adjacent the second partition and the walls thereof are imperforate for I asubstantial distance from the chamber wall are apertured for the remainder of the and 12. A device of the character described, comprising a shell, means forming an inlet chamber, a snubber chamber and a separating chamber in longitudinal succession in said shell, said "I! separating chamber longitudinal wall being genwith claim 5,

assasss eraliy cylindrical. gas inlet conduit means leading into said inlet chamber, said snubber chamber having an inlet opening in direct communi-'- cation and alignment with and spaced from said inlet conduit means, a plurality of apertured walled conduits passing through said snubber chamber and providing communication between said inlet chamber and said separating chamber, the axes of said conduits being uniformly oblique to the longitudinal axis of said separating cham- 'ber, the inlet ends of said conduits being in nonalignment with said inlet conduit means and the outlet ends of said conduits being adjacent the longitudinal wall of said separating chamber, and means at said longitudinal wall of said se arating chamber for trapp n solid particles whirling about the axis of said separating chambet, and gas outlet means leading out of said separating chamber.

13. A construction in accordance with claim 12, in which the obliquely arranged conduits have lips at the ends thereof opening into the separating chamber, said lips being arranged to defleet the emerging gases in such direction that the said obliqueness of their path is increased over that of the gases withinthe said conduits.

14. A device of the character described, comprising a shell, means forming an inlet chamber, a snubber chamber and a separating chamber in longitudinal succession in said shell, said secondary openings, open-ended, apertured .walled conduits passing through said snubber chamber and connecting each of said secondary openings to one of said openings in said second partition and providing communication between said inlet chamber and said separatin chamber, the axes of said apertured walled conduits being uniformly oblique with respect to the axis of said snubber chamber, whereby gases emerging from said conduits into said separating chamber are given a whirling motion about the axis of said separating chamber, and means at said longitudinal wall of said separating chamber iortrapping solid particles whirling about the axis of said separating chamber, and gas outlet means leading out of said separating chamber.

'16. A device of the class described, comprising a generally cylindrical shell, first and second spaced-apart transverse partitions dividing said shell into an inlet chamber, a snubber chamber and a separating chamber, a gas inlet conduit leading into said inlet chamber, said first partition having a primary opening therein at least substantially as large as the c oss sectional area of said inlet conduit and in direct communication and substantial alignment with said inlet conduit, said first partition having a plurality of secondary openings therein in nonseparating chamber longitudinal wall being gens erally cylindrical. gas inlet conduit means leading into said inlet chamber, said snubber chamber havin an inlet opening in direct communication and alignment with and spaced from said inlet conduit means, a plurality of apertured walled conduits passing through said snubber chamber and providing communication between said inlet chamber and said separating chamber, the interior of said snubber chamber being substantially free of obstruction whereby gases therein are substantially free to expand and pass into said conduits through the apertured walls thereof, the axes of said conduits being uniformly oblique to the lon itudinal axis of said separating chamber, the inlet ends of said conduits being in non-alignment with said inlet conduit means and the outlet ends of said conduits being adjacent the longitudinal wall of said separating chamber, said inlet chamber providing a transverse gas path between said inlet conduit mean and said apertured conduits at least substantially as large as the cross sectional area of said inlet conduit means, and means at said longitudinal wall of said separating chamber for trappin solid particles whirli g about the axis of said separating chamber, and gas outlet means leading out of said separating chamber.

15. A device of the character described, comprising a shell, first and second spaced-apart transverse partitions dividing said shell into an inlet chamber, a snubber chamber and a sepcratin chamber, the longitudinal wall of said separating chamber being generally cylindrical, a gas inlet conduit leading into said inlet chamber and having the outlet end thereof spaced from said first partition, said first partition having a primary opening therein in direct com munication and substantial alignment with said inlet conduit and a plurality of secondary openings therein in direct communication and nonalignment with said inlet conduit, said second partition having openings therein spaced from the center thereof and equal in number to said alignment with said inlet conduit and adjacent the cylindrical wall of said shell, said secondary openings being in unrestricted communication with the outlet end of said inlet conduit, said second partition having openings therein equal in number to said secondary openings and adjacent the cylindrical wall of said shell, open-ended,

apertured walled conduits passing through said.

snubber chamber and connecting each of said secondary openings to one or 'said openings in said second partition and providing communication between said inlet chamber and said separating chamber, the individual openings of each said connected pair of openings being uniformly angularly displaced one from the other with respect to' the axis of said cylindrical shell, whereby said apertured walled conduits extend through said snubber chamber uniformly obliquely with respect to the said axis, the cylindrical wall of said separating chamber having an opening therein, means forming a particle collecting chamber exteriorly of said opening, and an outlet conduit extending into said separating cham. ber from the wall thereof opposite said second partition, said outlet conduit walls being substantially imperforate for a substantial distance into said separating chamber from the wall thereof.

17. A device of the class described, comprising a, generally cylindrical-shell, first and second spaced-apart transverse partitions dividing said shell into an inlet chamber, a snubber chamber and a separating chamber, a. gas inlet conduit leading into said inlet chamber and having the outlet end thereof spaced from said first partition,

- said first partition having a, primary opening therein in direct communication and substantial alignment with said inlet conduit and a plurality of secondary openings therein in non-alignment with said inlet conduit, said second partition having openings therein spaced from the center thereof and equal in number to said secondary openings, a plurality of open-ended apertured walled conduits passing through said snubber chamber and connecting each of said secondary openings to one of said openings in said second partition and providing communication between said inlet chamber and sald separating chem in: chamber having a slot extendmg longmithe individual openings of each said connected dlnally thereof, and means formin n pair of openings being ansularly' displaced one ticle collecting chamber exterlorly 0! said slot,

from the other with respect to the axis of said said separating chamber having a. gas outl t shell, whereby the axes of said apertured walled 5 opening in s. wall thereo! opposite said e d conduits are oblique with respect to the axis partition.

of said shell, the cylindrical wall of said separat- RALPH L. LEADBE'I'TER. 

